Coming Clean about Pumice

I was just thinking about how unfortunate it is that most people don't know anything about geology. It's a really cool field of science. Part of the reason I think has to do with the fact that most people think geology is sort of useless. They think, what do rocks have to do with me? So instead of writing a novel about how untrue that is, I thought I would instead focus on one type of rock and use it as a small example of how geology impacts our lives.
Pumice. It's a light, porous, rock formed when water rich lava is extruded from volcanoes. Technically it is volcanic glass, like obsidian except with lots and lots of holes in it. When Karakatoa (located in Indonesia) erupted in the late 1800's pumice that formed during the blast actually floated (yep...rocks can float) all the way to the west coast of Africa. (As a side note, Krakatoa by S. Winchester is an amazing book! You should read it.)
So of what use is this to us? Well, you may not know it but pumice is all around us. It is used as landscaping rock (a red type called scoria), and we use it to exfoliate our skin. Pumice is also the main material in the mixture your dentist puts on your teeth during a cleaning that makes them feel smooth and fresh. Pumice is used in many cleaners as an abrasive (things like Soft Scrub etc.), It's sometimes used in cement when the construction projects require lighter weight materials. And it is super useful when placing drunken bets with friends that rocks can in fact float.
So the next time you are getting your teeth cleaned think about the fact that at some point in the past that pumice that is making your teeth all nice and shiny once resided as a liquid in the belly of a volcano. See I told you. Geology is awesome!